“…Judgment calls were necessary, because CHAT has strong family resemblances and yet is distinct from situated cognition, distributed cognition, legitimate peripheral participation, actor-network, and practice theories (see Barab, Evans, & Baek, 2004;Cole, Engeström, & Vasquez, 1997). Similarly, by and large not considered here were the growing corpus of important projects that find much sympathy with CHAT but (a) emphasize less the historical determinations of practical labor and historical conditions of culture, cognition, and learning and (b) adhere more to a discursive, semiotic, or multimodal perspective drawing on Mikhail Bakhtin or Michael K. Halliday (e.g., Franks & Jewitt, 2001;Kress, Jewitt, Ogborn, & Tsatsarelis, 2001; D. R. Russell, 1997;Wells, 1999Wells, , 2002. This procedure left us with about 350 texts, not all of which are referenced here to eliminate overlaps.…”